Electropolishing and anodizing method for brush holder apparatus

ABSTRACT

A method for treating a surface of a brush holder apparatus, where the brush holder apparatus is configured for use in a dynamoelectric machine, includes an electropolishing step that electropolishes the surface of the brush holder apparatus. An anodizing step anodizes the surface of the brush holder apparatus. The electropolishing step is performed before the anodizing step.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to a method forelectropolishing and anodizing a brush holder apparatus. Specifically,the subject matter disclosed herein relates to a method where theelectropolishing is used as a pretreatment for the subsequentanodization of a brush holder apparatus.

Conventional dynamoelectric machines include a rotor having windingsthat conduct electrical current during operation of the machine. As therotor rotates, rotating elements are used to conduct current to therotor windings from a source external to the rotor. The rotatingelements such as collector rings or commutators make contact withbrushes to conduct the current. As the brushes are stationary withrespect to the rotating elements, the brushes, which are made of carbon,wear due to friction and need periodic replacement.

Due to a desire to decrease downtime during operation of thedynamoelectric machine, brushes and brush holders are sometimes replacedduring operation of the dynamoelectric machine. In order to replacebrushes and brush holders safely, an operator uses a single hand (inorder to avoid conducting electrical current through the operator'sbody). Conventional brush holders can be heavy and unwieldy, makingbrush replacement both difficult and dangerous.

BRIEF DESCRIPTION OF THE INVENTION

According to an aspect of the disclosure, a method for treating asurface of a brush holder apparatus, where the brush holder apparatus isconfigured for use in a dynamoelectric machine, includes anelectropolishing step that electropolishes the surface of the brushholder apparatus. An anodizing step anodizes the surface of the brushholder apparatus. The electropolishing step is performed before theanodizing step. A cleaning step may be used to clean the surface of thebrush holder apparatus to remove contaminants, and the cleaning step isperformed before the electropolishing step. A cleaning step may also beperformed before the anodizing step and after the electropolishing step.The electropolishing step may be performed with the followingparameters: a 140° F. to 170° F. temperature, a voltage of 12 volts to24 volts, an amperage of 15 amps per square foot to 50 amps per squarefoot, a phosphoric acid based electrolyte, and a dwell time of 4 minutesto 8 minutes. The electropolishing step may also include an agitatingstep that agitates the brush holder apparatus during theelectropolishing step. The anodizing step may be performed with thefollowing parameters, a chromic acid bath, a bath temperature of 100° F.to 130° F., a current density of about 3 amps per square foot, and avoltage of 18 volts to 24 volts. The anodizing step may be performed fora time to create an anodizing coating of 0.02 mils to 0.7 mils thick.The anodizing step may also be performed with the following parameters,a sulfuric acid bath, a bath temperature of 60° F. to 80° F., a currentdensity of 5 to 18 amps per square foot, a voltage of 18 to 24 volts,and performed for a time to create an anodizing coating of 0.07 mils to1.0 mils thick. The anodizing step may also be performed with thefollowing parameters, a sulfuric acid bath, a bath temperature of 25° F.to 35° F., a current density of 24 to 40 amps per square foot, a voltageof 18 to 75 volts, and performed for a time to create an anodizingcoating of 0.5 mils to 4.0 mils thick.

According to another aspect of the disclosure, a method for treating asurface of a brush holder apparatus, includes a cleaning step forcleaning the surface to remove contaminants. An electropolishing step isused for electropolishing the surface of the brush holder apparatus. Ananodizing step is used for anodizing the surface of the brush holderapparatus. The electropolishing step is performed before the anodizingstep, and the brush holder apparatus is configured for use in adynamoelectric machine.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of this disclosure will be more readilyunderstood from the following detailed description of the variousaspects of the disclosure taken in conjunction with the accompanyingdrawings that depict various embodiments of the disclosure, in which:

FIG. 1 illustrates a partial perspective view of a single brush holderinstalled on a collector horseshoe, according to an aspect of thepresent disclosure.

FIG. 2 illustrates a perspective view of the stationary support member,according to an aspect of the present disclosure.

FIG. 3 illustrates a perspective rear view of the stationary supportmember as shown in FIG. 2, according to an aspect of the presentdisclosure.

FIG. 4 illustrates a perspective front view of the brush holder,according to an aspect of the present disclosure.

FIG. 5 illustrates a perspective rear view of the brush holder,according to an aspect of the present disclosure.

FIG. 6 illustrates a bottom view of the brush holder and the cam membersused to retain the brushes, according to an aspect of the presentdisclosure.

FIG. 7 illustrates a side view of the brush holder, according to anaspect of the present disclosure.

FIG. 8 illustrates a method for electropolishing and anodizing the brushholder apparatus, according to an aspect of the present disclosure.

FIGS. 9-12 illustrate the cleaning, electropolishing and anodizing stepsfor the brush holder apparatus, according to an aspect of the presentdisclosure.

It is noted that the drawings of the invention are not necessarily toscale. The drawings are intended to depict only typical aspects of theinvention, and therefore should not be considered as limiting the scopeof the invention. In the drawings, like numbering represents likeelements between the drawings.

DETAILED DESCRIPTION OF THE INVENTION

Aspects of the disclosure provide for a method for electropolishing andanodizing a brush holder apparatus configured to conduct electricalcurrent between a brush and a rotating element of a dynamoelectricmachine (e.g., an electrical generator or electrical motor). Inparticular, aspects provide for a method where the electropolishing isdone before the anodizing.

As described herein, conventional dynamoelectric machines include arotor having windings that conduct electrical current during operationof the machine. As the rotor rotates, rotating elements are used toconduct current to the rotor windings from a source external to therotor. The rotating elements such as collector rings or commutators makecontact with brushes to conduct the current. As the brushes arestationary with respect to the rotating elements, the brushes, which aremade of carbon, wear due to friction and need periodic replacement.

Due to a desire to decrease downtime during operation of thedynamoelectric machine, brushes are sometimes replaced during operationof the dynamoelectric machine. In order to replace brushes safely, anoperator uses a single hand (in order to avoid conducting electricalcurrent through the operator's body). Conventional brush holders can beheavy and unwieldy, making brush replacement both difficult anddangerous.

In contrast to conventional brush holders, aspects of the disclosureinclude a brush holder apparatus for a dynamoelectric machine having ananodized outer surface that provides electrical insulation. Theinsulating, anodized surface of the brush holder apparatus ensures thatcurrent flows through the brush and not the supporting components of thebrush holder assembly. If the supporting parts of the brush holderassembly (e.g., the stationary support member, the brush holder, etc.)had current flowing through them, then a shock hazard would exist to anoperator trying to manipulate the brush holder assembly.

FIG. 1 illustrates a partial perspective view of a single brush holderapparatus installed on a collector horseshoe, according to an aspect ofthe present disclosure. A brush mount or collector horseshoe 110 ismounted over a collector ring 120. The collector ring rotates along withthe rotor (not shown). A plurality of brushes and corresponding brushholders are attached to the collector horseshoe and are distributed atleast partially around the collector ring. In this example, only asingle brush holder apparatus 100 is shown attached to the collectorhorseshoe 110. The brush holder apparatus 100 may be bolted or screwedto the collector horseshoe, or any other suitable method may beemployed. The brush holder apparatus 100 includes a stationary supportmember 102 and a brush holder 104. The stationary support member 102 isconfigured for electrical connection to the collector mount (i.e.,collector horseshoe 110), for example, by being fabricated of aconductive material or including a conductive material. The brush holder104 is configured to retain the brush(es) (contained therein) at leastin the axial and circumferential directions.

FIG. 2 illustrates a perspective view of the stationary support member102, according to an aspect of the present disclosure. The stationarysupport member 102 includes at least one groove 210 (two are shown inFIG. 2) and a fork electrical connector 220. The fork electricalconnector 220 may extend to one or both sides of the stationary supportmember, or alternatively the fork electrical connector may only becentrally located without extending to the sides of the stationarysupport member. A tapered slot 230 is located in an upper portion of thestationary support member 102, and the slot 230 is configured forcooperation with a locking pin 450 on the brush holder. The locking pincould also be replaced by a bar or latch or protrusion or disc with aramped surface. The tapered nature of slot 230 acts to force the brushholder down into the connector 220 as the locking pin 450 is rotated. Abar 240 is located near a bottom end of the stationary support member102, and this bar is configured to engage and restrain a cam on thebrush holder 104. The bar 240 also serves to limit the distance thebrush holder 104 can be inserted into the stationary support member 102.The brush holder 104 is fixed in position relative to the stationarysupport member 102 between the locking pin 450 at top and the bar 240 atthe bottom. The bar 240 is fully contained within the profile of thestationary support member 102 and does not protrude past that profile. Aplurality of holes 250 are provided and are configured to facilitateattachment of the stationary support member 102 to the collector mount(or collector horseshoe 110). The holes 250 may be internally threadedfor use with mechanical fasteners, such as bolts or screws. In addition,the holes 250 may be provided on both sides of the stationary supportmember 102 so that they are configured to attach a plurality ofstationary support members together in a stacked or side-by-sidearrangement. This may be desired when multiple brushes are stackedside-by-side. For example, 3, 4, 5, 6, 7 or more brushes may be arrangedat one circumferential location on collector horseshoe 110. A conductivebar 260 is located on one or more sides of the stationary support member102. The conductive bar 260 is configured to provide electricalconductivity with the collector mount (collector horseshoe 110) and/or asecond stationary support member (e.g., connected to the side of thefirst stationary support member).

FIG. 3 illustrates a perspective rear view of the stationary supportmember 102 as shown in FIG. 2, according to an aspect of the presentdisclosure. The conductive bar 260 passes through a portion of thestationary support member's main body 103, and is configured to provideelectrical conductivity with the collector mount 110 and the forkelectrical connector 220. This arrangement enables the stationarysupport member 102 to be fully electrically insulated and the current topass from the horseshoe 110 to the fork 220 through the conductive bar260. The holes 250 to mount to the horseshoe 110 are formed inconductive bar 260. In alternative embodiments, the conductive bar 260may be lengthened so that multiple stationary supports 102 could beattached to the same (longer) conductive bar 260. The conductive bar 260may be attached to the stationary support 102 and the fork electricalconnector 220 via bolts (not shown) that run down through tabs 270 andinto the stationary support, and into or through the conductive bar 260.In this example, one tab/boss 270 is shown on each side of theelectrical fork 220. The fork electrical connector 220 may also beformed integrally with the conductive bar 260.

The stationary support member 102 may be configured to accept one, two(as shown), three, or more brush holders. One aspect would be astationary support member that accepts one, two or three brushes, andmultiple stationary support members and can be arranged side-by-side forapplications needing a specific number of brushes at a givencircumferential location on the collector horseshoe. The stationarysupport member 102 and/or the brush holder may be formed substantially(or comprised) of aluminum, an aluminum alloy, stainless steel or anyother suitable electrically conductive or electrically non-conductivematerial as desired in the specific application. As one non-limitingexample only, the stationary support member 102 and the brush holder 104may be formed substantially (or comprised) of a passivated or anodizedaluminum, or a passivated or anodized aluminum alloy. This material willgive good strength while providing an electrically insulating orelectrically semi-insulating material. It is desired to minimize currentflow through the brush holder body and focus the current flow throughthe brushes and electrical path of the brush holder designed for thiscurrent flow. In addition, it would be desirable to minimize (or evenblock) any current flow to portions that may be grasped by a technicianduring insertion or removal. Also, it is desirable to avoid thepossibility of current arcing directly from the collector ring 120 tothe brush holder 104 or to the stationary support member 102 when abrush 432 is worn out and no longer able to be part of the path for thecurrent. At least a portion of a surface of at least one of thestationary support member and the brush holder is configured to besubstantially electrically insulating. For example, the handle of thebrush holder should be substantially electrically insulating to protecta technician during insertion or removal of the brush holder on anoperating machine. Alternatively, the stationary support member and thebrush holder may be formed substantially (or comprised) of a powdercoated or painted aluminum or a powder coated or painted aluminum alloyor a powder coated metallic or non-metallic material or a ceramic coatedmetallic or ceramic coated non-metallic material.

FIG. 4 illustrates a perspective front view of the brush holder 104,according to an aspect of the present disclosure. FIG. 5 illustrates aperspective rear view of the brush holder 104, according to an aspect ofthe present disclosure. The brush holder 104 is configured to bereleasably affixed to the stationary support member 102. At least onerail 410 is configured to slide along groove 210. In the example shownthe brush holder 104 includes two rails 410, one on each side of thebrush holder. A knife electrical connector 420 (shown in FIG. 5),configured to mate with the fork electrical connector 220, is located onthe rear of the brush holder 104. A brush retaining box 430 retains oneor more brushes 432 in the axial and circumferential directions. In theexample shown, box 430 retains two brushes 432. The brushes 432 arebiased radially downward by brush springs 434. Apertures 431 formwindows in the box 430 and allow the brushes 432 to be seen and visuallymonitored for wear.

The brush holder 104 includes a handle assembly 440 that includes anelectrically insulating handle 442 and an electrically insulating guard444 or shield that is located between the handle 442 and the brushconnector leads 436. The brush connector leads 436 carry high voltageand current while the dynamoelectric machine is operating, so thesepresent a hazard to be avoided. The electrically insulating handle 442and guard 444 will prevent a technician's hand from coming into contactwith the energized brush connector leads 436. The handle 442 and guard444 may be comprised of plastic, rubber, epoxy/fiberglass laminate,fiberglass, or any other suitable electrically insulating material.

The locking pin 450 is configured for cooperation with the tapered slot230 in the stationary support member 102. The handle assembly 440 canrotate, and as it rotates the locking pin 450 is rotated into, or outof, the tapered slot 230. The views of FIGS. 4 and 5 show the lockingpin 450 and handle 442 oriented in the locked position. In this lockedposition the locking pin 450 is fully inserted into the slot 230 and thetapered surface drives the locking pin radially downward. In otherwords, the handle assembly 440 is configured to be rotated about 90degrees, a 0 degree position configured so that the locking pin 450 isdisengaged from the tapered slot 230 so that the brush holder 104 may beremoved from the stationary support member 102. A 90 degree position (asshown in FIGS. 4 and 5) is configured so that the locking pin 450 isengaged in the tapered slot 230 so that the brush holder 104 is fullylocked into operating condition on the stationary support member 102. Byhaving the handle 442 oriented parallel to the locking pin 450 andhaving the locking pin 450 extend through the tapered slot 230, theoperator can easily see that the brush holder 104 is fully inserted andlocked in place within the stationary support 102.

A spring assembly 460 is housed within the handle assembly 440, and thespring assembly is mechanically connected to the brush terminalcompression plate 470 (two of which are shown). The brush terminalcompression plate may be one piece that extends through the shaft of thehandle, but it could also be fabricated from two pieces. The brushes 432are connected to the brush terminals 438 via brush connector leads (orpigtails) 436. The brush terminals 438 are electrically connected to theknife electrical connector 420. For example, the knife electricalconnector includes an electrically conductive base member that extendsunder each brush terminal 438, thereby making an electrically conductivepath. The spring assembly 460 biases the compression plates 470 downwardand this downward pressure retains the brush terminals in place andagainst the base member of the knife electrical connector 420. This isparticularly advantageous when the brush holder 104 is being inserted(or removed from) the stationary support member 102. It is advised touse only one hand when manually inserting or removing the brushes, andthe spring assembly ensures that a second hand is not required to keepthe brush terminals 438 in place. Once the brush holder 104 is fullyinserted into the stationary support member, the handle 442 is rotated90 degrees (into a locked position) and the tapered slot 230 forces thelocking pin 450 (as well as brush holder 104) radially downward applyingadditional force onto the brush terminals 438. An advantage of thisdesign is that the brush holder 104 is configured to clamp a brushterminal 438 between a terminal compression plate 470 and an opposingsurface of the brush holder (i.e., the electrically conductive basemember of knife electrical connector 420), so that the brush terminal isengaged or released manually, only by hand or without the use of anytools. All that is required is manual placement of the respective partsby hand. Minimizing or eliminating the use of specific tools can greatlysimplify and increase the safety of working around dynamoelectricmachines, especially when they are operating and energized.

As illustrated, the brush box 430 is configured to hold two brushes 432.However, the box 430 can be configured to hold one brush 432 (byreducing the width of the box) or three or more brushes (by increasingthe width of the box and providing additional individual brushapertures). The brush terminal 438 includes a downward bend located at aproximal end thereof. This bend helps to keep the brush terminal inplace under the compression plate 470. A hole or notch could also beprovided in the brush terminal that cooperates with a complementaryfeature on the terminal compression plate 470 or the electricallyconductive base member of knife electrical connector 420. For example,if the brush terminal 438 included a hole in the center thereof, thecompression plate 470 could have a complementary pin located to engagethe hole of the brush terminal. This complementary feature on the brushholder facilitates securing the brush terminal to the brush holder. Theinverse could also be used, with the brush terminal having acomplementary pin and the compression plate having the hole. With thisarrangement, the brush holder 104 is configured to electrically andmechanically connect the knife electrical connector 420 to the brushterminal 438, while both the knife electrical connector 420 and thebrush terminal 438 are electrically insulated from handle 442.

As the brush 432 wears down due to frictional contact with the rotorcollector ring 120, the brush spring 434 will keep the eroding surfaceof the brush 432 in contact with the rotor collector ring 120. The brushspring 434 is configured to press the brush 432 radially downward andagainst the collector ring 120, because the spring 434 is designed withtension to re-coil itself. In this manner, the coil at the top of thespring 434 wants to re-tighten or coil downward, thereby applying aradially downward force to brush 432. The spring 434 is clipped on thebottom of the brush holder 104. For example, a lower part of main bodyportion 411 of the brush holder is where the brush spring 434 attachesto the brush holder. The bottom of the brush spring 434 is U-shaped, andthe U-portion fits over and clips onto lower part of main body portion411. The brush spring 434 is also configured to be located in-line with,or offset by 90 degrees from, the cam member 610 configured forrestraining the brush 432 against the brush holder or box 430. Thisin-line arrangement is aligned so that any potential binding is reducedor eliminated and smooth operation is permitted between the spring 434,brush 432 and cam members 610.

FIG. 6 illustrates a bottom view of the brush holder 104 and the cammembers 610 used to retain the brushes 432, according to an aspect ofthe present disclosure. A cam member 610 is operably connected to theshaft 620 near a bottom of the brush holder 104. The cam member 610 isconfigured to retain the brush 432 against the brush holder or box 430until the brush holder 104 is fully inserted in the stationary supportmember 102. The cam member 610 may be constant-angle cam shaped, or havean arcuate toothed shape and is mounted with a spring 612 (e.g., atorsional spring) to shaft 620. The constant-angle cam shape and arcuatetoothed shape may be consistent with logarithmic spiral geometry. Thatmeans that no matter how much the cam member 610 is rotated in order toreach the brush 432 surface, the cam 610 will contact the brush 432 withthe same angle and same large force to resist sliding of the brushwithin the brush holder 104. Not all brushes may be exactly the samesize so it is important that each cam member 610 is free toindependently rotate on the shaft 620 to the fill the actual gap betweenthe shaft 620 and the corresponding brush 432 surface.

FIG. 7 illustrates a side view of the brush holder 104, according to anaspect of the present disclosure. The knife electrical connector 420 isconfigured so that it slides into and makes electrical contact with thefork electrical connector 220. The knife electrical connector 420extends down to a point below a top of the brush holder box 430.

FIG. 8 illustrates a method 800 for electropolishing and anodizing thebrush holder apparatus, according to an aspect of the presentdisclosure. An optional cleaning step 810 cleans the surface of thebrush holder apparatus 100 to remove contaminants. The contaminants maybe particulate matter, grease or oils, or any other undesirable materialcurrently on the brush holder apparatus. The brush holder apparatus maybe cleaned or desmutted with a liquid acid solution. For example, theexisting oxide layer is cleaned off in a bath of caustic soda, and afterthe caustic soda bath, the aluminum is washed in a bath made of halfwater and half 70% nitric acid.

In step 820 the surface of the brush holder apparatus iselectropolished. In electropolishing the brush holder apparatus (or partthereof) is the anode (positive voltage) and the cathode is connected toa negative voltage terminal. The brush holder apparatus and cathode areimmersed in an electrolyte bath and a voltage is applied for a specifiedtime while the bath is maintained in a predetermined temperature range.The effect removes material from the surface of the brush holderapparatus, and polishes, deburrs or passivates the surface. Theresulting electropolished surface provides a better surface for theapplication of a subsequent anodizing layer, which will have fewerdefects and hence better electrical insulating performance. Exampleelectropolishing parameters are, a phosphoric acid basebath/electrolyte, a bath temperature of about 140° F. to about 170° F.,a DC rectified voltage of about 12 to 24 volts, an amperage of about 15to 50 amps per square foot, and a dwell time (i.e., time spent in thebath exposed to DC voltage) of about 4 to 8 minutes. After theelectropolishing step 820 the brush holder apparatus may be cleanedagain in step 830, which may be similar to cleaning step 810.

In step 840, the electropolished brush holder apparatus (or partthereof) is now anodized. Anodization is an electrolytic passivationprocess used to increase the thickness of a natural oxide layer on thesurface of metal parts. In anodizing the brush holder apparatus (or partthereof) is the anode (positive voltage) and the cathode is connected toa negative voltage terminal. The brush holder apparatus and cathode areimmersed in an acid bath and a voltage is applied for a specified timewhile the bath is maintained in a predetermined temperature range. Theeffect creates an insulating oxide layer on the surface of the brushholder apparatus. The resulting anodized surface provides an insulatinglayer to ensure that current only flows through the brush andcorresponding electrical connection, and not through undesired portionsof the brush holder apparatus (e.g., the stationary supporting member,brush box or handle). Example anodizing parameters are provided for TypeI, Type II and Type II anodizing layers. For a Type I anodizingtreatment, a chromic acid bath is used with a bath temperature of about100° F. to about 130° F., a DC rectified voltage of about 18 to 24volts, an amperage of about 3 amps per square foot, and a dwell timesufficient to create an anodizing coating of about 0.02 mils (one milequals 0.001 inches) to 0.7 mils thick. For a Type II anodizingtreatment, a sulfuric acid bath is used with a bath temperature of about60° F. to 80° F., a DC rectified voltage of about 18 to 24 volts, anamperage of about 5 to 18 amps per square foot, and a dwell timesufficient to create an anodizing coating of about 0.07 mils to 1.0 milsthick. For a Type III anodizing treatment, a sulfuric acid bath is usedwith a bath temperature of about 25° F. to 35° F., a DC rectifiedvoltage of about 18 to 75 volts, an amperage of about 24 to 40 amps persquare foot, and a dwell time sufficient to create an anodizing coatingof about 0.5 mils to 4.0 mils thick.

FIGS. 9-12 illustrate the cleaning, electropolishing and anodizing stepsfor the brush holder apparatus 100 (or part thereof). In FIG. 9 a brushholder apparatus 100 is selected and contains contaminants 901 to beremoved. The brush holder has a surface 910. Contaminants 901 are showncovering the entire surface, but contaminants 901 may only be present inselected areas on surface 910, with other areas of surface 910 beingcontaminant free. FIG. 10 shows the brush holder apparatus aftercleaning, and the contaminants 901 have been removed. FIG. 11 shows thebrush holder apparatus after electropolishing, and the electropolishedsurface 1110 is smoother than the previous surface 910. FIG. 12 showsthe brush holder apparatus 100 after anodizing, and the anodized surface1210 is now formed on the surface of the brush holder apparatus to adesired thickness.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Approximating language, as used herein throughout the specification andclaims, may be applied to modify any quantitative representation thatcould permissibly vary without resulting in a change in the basicfunction to which it is related. Accordingly, a value modified by a termor terms, such as “about,” “approximately” and “substantially,” are notto be limited to the precise value specified. In at least someinstances, the approximating language may correspond to the precision ofan instrument for measuring the value. Here and throughout thespecification and claims, range limitations may be combined and/orinterchanged, such ranges are identified and include all the sub-rangescontained therein unless context or language indicates otherwise. Theterms “about” and “approximately” as applied to a particular value of arange applies to both values, and unless otherwise dependent on theprecision of the instrument measuring the value, may indicate +/−10% ofthe stated value(s).

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

1. A method for treating a surface of a brush holder apparatus, thebrush holder apparatus for use in a dynamoelectric machine, the methodcomprising: electropolishing the surface of the brush holder apparatus;anodizing the surface of the brush holder apparatus; and wherein theelectropolishing step is performed before the anodizing step.
 2. Themethod of claim 1, further comprising: cleaning the surface to removecontaminants; and wherein the cleaning step is performed before theelectropolishing step.
 3. The method of claim 1, further comprising:cleaning the surface to remove contaminants; and wherein the cleaningstep is performed before the anodizing step and after theelectropolishing step.
 4. The method of claim 1, the electropolishingstep performed with the following parameters: a 140° F. to 170° F.temperature; a voltage of 12 volts to 24 volts; an amperage of 15 ampsper square foot to 50 amps per square foot; a phosphoric acid basedelectrolyte; and a dwell time of 4 minutes to 8 minutes.
 5. The methodof claim 4, the electropolishing step further comprising: agitating thebrush holder apparatus during the electropolishing.
 6. The method ofclaim 1, the anodizing step performed with the following parameters: achromic acid bath; a bath temperature of 100° F. to 130° F.; a currentdensity of about 3 amps per square foot; and a voltage of 18 volts to 24volts.
 7. The method of claim 6, the anodizing step performed for a timeto create an anodizing coating of 0.02 mils to 0.7 mils thick.
 8. Themethod of claim 1, the anodizing step performed with the followingparameters: a sulfuric acid bath; a bath temperature of 60° F. to 80°F.; a current density of 5 to 18 amps per square foot; and a voltage of18 to 24 volts.
 9. The method of claim 8, the anodizing step performedfor a time to create an anodizing coating of 0.07 mils to 1.0 milsthick.
 10. The method of claim 1, the anodizing step performed with thefollowing parameters: a sulfuric acid bath; a bath temperature of 25° F.to 35° F.; a current density of 24 to 40 amps per square foot; and avoltage of 18 to 75 volts.
 11. The method of claim 10, the anodizingstep performed for a time to create an anodizing coating of 0.5 mils to4.0 mils thick.
 12. A method for treating a surface of a brush holderapparatus, the method comprising: cleaning the surface to removecontaminants; electropolishing the surface of the brush holderapparatus; anodizing the surface of the brush holder apparatus; andwherein the electropolishing step is performed before the anodizingstep, and the brush holder apparatus is configured for use in adynamoelectric machine.
 13. The method of claim 12, wherein the cleaningstep is performed once before the electropolishing step and once beforethe anodizing step.
 14. The method of claim 12, the electropolishingstep performed with the following parameters: a 140° F. to 170° F.temperature; a voltage of 12 volts to 24 volts; an amperage of 15 ampsper square foot to 50 amps per square foot; a phosphoric acid basedelectrolyte; and a dwell time of 4 minutes to 8 minutes.
 15. The methodof claim 14, the electropolishing step further comprising: agitating thebrush holder apparatus during the electropolishing step.
 16. The methodof claim 14, the anodizing step performed with the following parameters:a chromic acid bath; a bath temperature of 100° F. to 130° F.; a currentdensity of about 3 amps per square foot; and a voltage of 18 volts to 24volts.
 17. The method of claim 16, the anodizing step performed for atime to create an anodizing coating of 0.02 mils to 0.7 mils thick. 18.The method of claim 14, the anodizing step performed with the followingparameters: a sulfuric acid bath; a bath temperature of 60° F. to 80°F.; a current density of 5 to 18 amps per square foot; and a voltage of18 to 24 volts.
 19. The method of claim 18, the anodizing step performedfor a time to create an anodizing coating of 0.07 mils to 1.0 milsthick.
 20. The method of claim 14, the anodizing step performed with thefollowing parameters: a sulfuric acid bath; a bath temperature of 25° F.to 35° F.; a current density of 24 to 40 amps per square foot; a voltageof 18 to 75 volts; and wherein the anodizing step is performed for atime to create an anodizing coating of 0.5 mils to 4.0 mils thick.